title: Physiological responses of three marine microalgae exposed to cypermethrin.
abstract: The effects of cypermethrin on physiological responses of three typical marine microalgal species Skeletonema costatum (Bacillariophyceae), Scrippsiella trochoidea (Dinophyceae), and Chattonella marina (Raphidophyceae), were investigated by 96-h growth tests in a batch-culture system. The 96-h median inhibition concentrations (IC(50)) were 71.4, 205, and 191 μg L(-1) for S. costatum, S. trochoidea, and C. marina, respectively. Quick and significant physiological responses occurred when algal cells were exposed to cypermethrin, and all biochemical parameters varied significantly within 6- or 12-h exposure. Cypermethrin affected algal growth, protein content, and superoxide dismutase (SOD) activity by stimulation at low concentrations (1, 5 μg L(-1)) and inhibition at high concentrations (>50 μg L(-1)). A general increase in malondialdehyde (MDA) level was observed in all test groups, which suggested that the toxic effects of cypermethrin were probably exerted through free radical generation. These results suggest that the activation of SOD and promotion of protein at early exposure are important to counteract the oxidative stress induced by cypermethrin, and the inactivation of SOD may be crucial to the growth inhibition of microalgae by cypermethrin.
authors.affiliation: College of Life Science and Technology, Jinan University, Guangzhou, 510632, People's Republic of China. twzh@jnu.edu.cn
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Xiang-Ping
authors.initials: XP
authors.lastname: Nie
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Yue
authors.forename: Xin
authors.initials: X
authors.lastname: Li
mesh_terms: D017377:Diatoms / Q000187:drug effects* / Q000502:physiology; D007306:Insecticides / Q000009:adverse effects; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D058086:Microalgae / Q000187:drug effects* / Q000502:physiology; D018384:Oxidative Stress; D011722:Pyrethrins / Q000009:adverse effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000009:adverse effects
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C017160:cypermethrin; D008315:Malondialdehyde; D013482:Superoxide Dismutase